Results 11 to 20 of about 15,587,481 (320)
On Positivity Sets for Helmholtz Solutions
Vietnam Journal of Mathematics, 2023 AbstractWe address the question of finding global solutions of the Helmholtz equation that are positive in a given set. This question arises in inverse scattering for penetrable obstacles. In particular, we show that there are solutions that are positive on the boundary of a bounded Lipschitz domain.
Pu-Zhao Kow +2 more
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Multiple positive solutions for a Schrödinger logarithmic equation [PDF]
Discrete and Continuous Dynamical Systems. Series A, 2019 This article concerns with the existence of multiple positive solutions for the following logarithmic Schr\"{o}dinger equation $$ \left\{ \begin{array}{lc} -{\epsilon}^2\Delta u+ V(x)u=u \log u^2, & \mbox{in} \quad \mathbb{R}^{N}, \\ %u(x)>0, & \mbox{in}
C. O. Alves, Chao Ji
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Positive solutions for nonlinear parametric singular Dirichlet problems [PDF]
Bulletin of Mathematical Sciences, 2018 We consider a nonlinear parametric Dirichlet problem driven by the p-Laplace differential operator and a reaction which has the competing effects of a parametric singular term and of a Carathéodory perturbation which is ($$p-1$$p-1)-linear near $$+\infty
N. Papageorgiou +2 more
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, 2020 In this paper, we investigate the existence of positive solutions for the new class of boundary value problems via ψ -Hilfer fractional differential equations.
H. Afshari, E. Karapınar
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Positive Solutions of Difference Equations [PDF]
Proceedings of the American Mathematical Society, 1990 Proceedings of the American Mathematical ...
Philos, C. G., Sficas, Y. G.
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Positive solutions for nonlinear nonhomogeneous parametric Robin problems [PDF]
, 2018 We study a parametric Robin problem driven by a nonlinear nonhomogeneous differential operator and with a superlinear Carath\'eodory reaction term. We prove a bifurcation-type theorem for small values of the parameter. Also, we show that as the parameter
Nikolaos S. Papageorgiou +2 more
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Multiple positive solutions to elliptic boundary blow-up problems [PDF]
, 2016 We prove the existence of multiple positive radial solutions to the sign-indefinite elliptic boundary blow-up problem \[ \left\{\begin{array}{ll} \Delta u + \bigl(a^+(\vert x \vert) - \mu a^-(\vert x \vert)\bigr) g(u) = 0, & \; \vert x \vert < 1, \\ u(x)
Aftalion +44 more
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Positive solutions for the Robin p-Laplacian problem with competing nonlinearities
Advances in Calculus of Variations, 2019 We consider a parametric nonlinear elliptic equation driven by the Robin p-Laplacian. The reaction term is a Carathéodory function which exhibits competing nonlinearities (concave and convex terms).
L. Gasiński, N. Papageorgiou
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Algebraic Systems with Positive Coefficients and Positive Solutions
Mathematics, 2022 The paper is devoted to the existence, uniqueness and nonuniqueness of positive solutions to nonlinear algebraic systems of equations with positive coefficients. Such systems appear in large numbers of applications, such as steady-state equations in continuous and discrete dynamical models, Dirichlet problems, difference equations, boundary value ...
Ana Maria Acu +2 more
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Calculus of Variations and Partial Differential Equations, 2019 In this paper, we study a nonlinear Dirichlet problem of p-Laplacian type with combined effects of nonlinear singular and convection terms. An existence theorem for positive solutions is established as well as the compactness of solution set.
Zhenhai Liu, D. Motreanu, Shengda Zeng
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